无法从struts2中的值堆栈获取值(Can't get value from value stack in struts2)

我使用struts 2，我想使用struts标签。 我想用

<s:select list="types" name="list"/>

从值堆栈中获取列表，这是我的操作代码

ValueStack valueStack = ServletActionContext.getContext().getValueStack(); valueStack.pop(); valueStack.push(types);

但它没有用。这是错误信息

HTTP Status 500 - tag 'select', field 'list', name 'list': The requested list key '#types' could not be resolved as a collection/array/map/enumeration/iterator type. Example: people or people.{name} - [unknown location]

但是，如果我将列表放入requestScope.It确实有效，就像这样<s:select list="types" name="#request.types"/>

所以我该怎么做？

I use struts 2 ,and I want to use struts tag. I want to use

<s:select list="types" name="list"/>

to get a list from the value stack,Here is my action code

ValueStack valueStack = ServletActionContext.getContext().getValueStack(); valueStack.pop(); valueStack.push(types);

But it didn't work.Here is the error message

HTTP Status 500 - tag 'select', field 'list', name 'list': The requested list key '#types' could not be resolved as a collection/array/map/enumeration/iterator type. Example: people or people.{name} - [unknown location]

However if I put the list into the requestScope.It did work,like this<s:select list="types" name="#request.types"/>

So what should I do?

最满意答案

正如Walid所说，我应该在你的动作类中有一个getTypes（）方法，而不是直接使用值栈。

所以我改变了我的代码：

List<String> types ; public List<String> getTypes() { return types; } types = dailyNewsService.getAllTypes();

为了获得成功，请实现Preparable Interface并在其中加载“静态”数据：

@Override public void prepare() throws Exception { types = dailyNewsService.getAllTypes(); }

As Walid said, i should have a getTypes() method in your action class instead of working directly with the value stack.

So I changed my code like this:

List<String> types ; public List<String> getTypes() { return types; } types = dailyNewsService.getAllTypes();

For a succesful living, implement Preparable Interface and load there your "static" data:

@Override public void prepare() throws Exception { types = dailyNewsService.getAllTypes(); }无法从struts2中的值堆栈获取值(Can't get value from value stack in struts2)

我使用struts 2，我想使用struts标签。 我想用

<s:select list="types" name="list"/>

从值堆栈中获取列表，这是我的操作代码

ValueStack valueStack = ServletActionContext.getContext().getValueStack(); valueStack.pop(); valueStack.push(types);

但它没有用。这是错误信息

HTTP Status 500 - tag 'select', field 'list', name 'list': The requested list key '#types' could not be resolved as a collection/array/map/enumeration/iterator type. Example: people or people.{name} - [unknown location]

但是，如果我将列表放入requestScope.It确实有效，就像这样<s:select list="types" name="#request.types"/>

所以我该怎么做？

I use struts 2 ,and I want to use struts tag. I want to use

<s:select list="types" name="list"/>

to get a list from the value stack,Here is my action code

ValueStack valueStack = ServletActionContext.getContext().getValueStack(); valueStack.pop(); valueStack.push(types);

But it didn't work.Here is the error message

HTTP Status 500 - tag 'select', field 'list', name 'list': The requested list key '#types' could not be resolved as a collection/array/map/enumeration/iterator type. Example: people or people.{name} - [unknown location]

However if I put the list into the requestScope.It did work,like this<s:select list="types" name="#request.types"/>

So what should I do?

最满意答案

正如Walid所说，我应该在你的动作类中有一个getTypes（）方法，而不是直接使用值栈。

所以我改变了我的代码：

List<String> types ; public List<String> getTypes() { return types; } types = dailyNewsService.getAllTypes();

为了获得成功，请实现Preparable Interface并在其中加载“静态”数据：

@Override public void prepare() throws Exception { types = dailyNewsService.getAllTypes(); }

As Walid said, i should have a getTypes() method in your action class instead of working directly with the value stack.

So I changed my code like this:

List<String> types ; public List<String> getTypes() { return types; } types = dailyNewsService.getAllTypes();

For a succesful living, implement Preparable Interface and load there your "static" data:

@Override public void prepare() throws Exception { types = dailyNewsService.getAllTypes(); }